WO2016104979A1 - Adhesive composition, adhesive film formed from same, and display member comprising same - Google Patents

Abstract

An adhesive composition according to the present invention comprises: a monomer mixture comprising a comonomer and (meth)acrylate having a hydroxyl group; and nanoparticles, wherein the nanoparticles comprise silicon-based polymers, and have an average particle diameter of about 5 nm to 800 nm.

Description

Pressure-sensitive adhesive composition, pressure-sensitive adhesive film formed therefrom and display member including the same

The present invention relates to an adhesive composition, an adhesive film formed therefrom, and a display member including the same.

The transparent adhesive film is an adhesive film, which is used for interlayer adhesion for laminating components in an optical display device or touch screen attachment of a mobile phone.

In particular, the capacitive touchpad of the optical display device is attached to a window or a film by an adhesive film, thereby exhibiting characteristics by detecting a change in capacitance of the window or film. In the touchpad, the adhesive film is laminated between the window glass and the TSP sensor glass.

The transparent adhesive film transmits more than 97% of light and functions as glass, but has the advantage of increasing the screen clarity and good adhesiveness compared to the conventional double-sided tape. The transparent adhesive film may be used not only for mobile phones but also for tablet PCs and TVs having a large and large display screen.

In recent years, the use environment, storage environment, and / or manufacturing environment of the optical display device have been severe, and as the interest in the flexible optical display device has increased, various physical properties are required. In particular, in order to apply to a flexible display, a viscoelastic property is maintained at a wide temperature range, and a transparent adhesive film having excellent recovery characteristics is required.

Prior art in this regard is disclosed in Korean Patent Laid-Open Publication No. 2007-0055363.

An object of the present invention is to provide a pressure-sensitive adhesive composition, a pressure-sensitive adhesive film formed therefrom, and a display member including the same, while maintaining excellent viscoelastic properties and excellent recovery properties in a wide temperature range.

Another object of the present invention is to provide an adhesive composition having high transparency and excellent reliability under severe conditions, an adhesive film formed therefrom, and a display member including the same.

One aspect of the present invention is a pressure-sensitive adhesive composition is a monomer mixture comprising a (meth) acrylate having a hydroxyl group and a comonomer, and a composition comprising nanoparticles, the nanoparticles comprise a silicone-based polymer, the average particle diameter is about 5 nm to about 800 nm.

Another aspect of the present invention, the pressure-sensitive adhesive film may be formed of the pressure-sensitive adhesive composition.

Another aspect of the present invention, the display member may include an optical film and any one of the above adhesive film on one side or both sides of the optical film.

The present invention has excellent adhesive strength, viscoelastic properties are maintained in a wide temperature range, excellent recovery properties, high transparency, excellent reliability under severe conditions, pressure-sensitive adhesive film formed therefrom and a display member comprising the same Has the effect of providing.

1 is a cross-sectional view of a display member of one embodiment of the present invention.

2 is a conceptual diagram of a specimen for measuring T-peel peel strength.

3 is a cross-sectional view and a plan view of a specimen for measuring the recovery force.

As used herein, "(meth) acrylate" may mean acrylate and / or methacrylate.

As used herein, "copolymer" may include oligomers, polymers or resins.

In the present specification, "comonomer" is a monomer that polymerizes with (meth) acrylate having a hydroxyl group, and is not limited as long as it is capable of polymerization with (meth) acrylate having a hydroxyl group.

As used herein, "(meth) acrylic copolymer" may mean a copolymer of an acrylic monomer mixture and nanoparticles.

In the present specification, the "glass transition temperature" of the monomer may refer to the glass transition temperature measured by DSC measurement of TA Instrument for the homopolymer of the monomer to be measured. Specifically, the temperature of the monomer to be measured is raised to about 100 ° C. at a rate of about 20 ° C./min, and then cooled to about −180 ° C. at the same rate, and then about 100 at a rate of about 10 ° C./min. After obtaining the data of the endothermic transition curve when heated to ℃, the inflection point of the endothermic transition curve can be determined as the glass transition temperature.

In the present specification, "average particle diameter" is a particle diameter of nanoparticles expressed in Z-average values measured in an aqueous solvent or an organic solvent using a Zetasizer nano-ZS device manufactured by Malvern.

As used herein, the term "core-shell structure" may mean a conventional core-shell structure, and also includes a structure in which the core or the shell is several layers, and the "outer layer" refers to the outermost layer of the various layers. By "core-shell particles" is meant nanoparticles having a core-shell structure.

In the present specification, "T-peel peel strength for corona treated polyethylene terephthalate (PET) film" means a value measured by the measuring method of the following i) ~ v).

i) The pressure-sensitive adhesive composition is applied to a release treated PET (polyethylene terephthalate) film, and irradiated with an ultraviolet light amount of about 2000 mJ / cm ² to prepare a pressure-sensitive adhesive film and a pressure-sensitive adhesive sheet of about 100 ㎛ thickness.

ii) PET film of about 150 mm × 25 mm × 75 μm (width × length × thickness) subjected to about 2 corona treatments (total dose: about 156 doses) while discharging at a dose of about 78 doses using a corona treatment machine. Prepare.

iii) a pressure-sensitive adhesive film sample of about 100 mm × 25 mm × 100 μm (width × length × thickness) was obtained from the pressure-sensitive adhesive sheet, and the corona-treated side of the PET film was laminated on both sides of the pressure-sensitive adhesive film sample, respectively. , To prepare the specimen shown in (a) of FIG.

iv) Autoclave the specimen at about 3.5 bar at 50 ° C. for about 1,000 seconds and fix the specimen to the TA.XT_Plus Texture Analyzer (Stable Micro System).

v) T-peel peel strength is measured by fixing one PET film on the TA.XT_Plus Texture Analyzer and pulling the other PET film at a speed of about 50 mm / min. (See FIG. 2 (b))

In the present specification, "T-peel peel strength against corona treated polyethylene terephthalate (PET) film (hereinafter, non-corona PET)" means that the PET film of ii) of the measuring method is not subjected to corona treatment. Except for the "t-peel peel strength of the corona treated polyethylene terephthalate (PET) film" means the peel strength measured in the same manner as the measuring method.

In the present specification, the "recovery force" is when both ends of the PET (polyethylene terephthalate) film (thickness: about 75 μm) of width X length (about 50 mm × about 20 mm) are referred to as the first and second ends, respectively. , The end portions of each of the two PET films are adhered to each other by an adhesive film having a width × length (about 20 mm × about 20 mm), and the first ends of the PET film / adhesive film / PET film are adhered in the order of the second ends of the PET films. The area of contact between the PET film and the pressure-sensitive adhesive film is measured with a specimen that is horizontal x vertical (about 20 mm x about 20 mm). 3 (a) and (b), referring to FIG. 3 (a), the jig is fixed to both ends of the non-adhesive PET film in the specimen at room temperature (about 25 ° C.). One jig is fixed, and the other jig is about 1000% of the thickness of the adhesive film (unit: μm) at a speed of about 300 mm / min (about 10 times the initial thickness of the adhesive film, X ₀ ) After pulling as much as it is maintained for about 10 seconds, the adhesive film is restored to the same speed (about 300 mm / min) at the speed of pulling the adhesive film stretched length when the force of about 0 kPa applied to the adhesive film X _f ( Unit: μm), the recovery force (%) is a value calculated by the following equation (2):

[Equation 2]

Recovery Force (%) = (1- (X _f / X ₀ ))? 100

At this time, the initial thickness of the adhesive film may be 20 ㎛ to 300 ㎛. The recovery power can be measured with a TA.XT_Plus Texture Analyzer (Stable Micro System). The recovery force can be measured at 25 ° C.

In the present specification, the "elongation rate" is a thickness of about 100 μm, about 5 cm × about 5 cm, and then rolled up to closely adhere to the TA, TA (TA.XT_Plus Texture Analyzer (Stable Micro System)). When both ends are fixed and stretched at a speed of about 300 mm / min, it means that the length of the breaking moment of the adhesive film is expressed as a ratio (%) to the length (100%) before stretching.

In the present specification, the "bubble generating area" is a PET having a thickness of about 50 μm on one side of an adhesive film (about 13 cm × about 3 cm, thickness of about 100 μm) and PET having a thickness of about 100 μm on the back side of the adhesive film. The adhesive film is bent in a direction of about 50 μm PET so that the horizontal length is about 1/2 between parallel frames of about 1 cm interval, and aged at about 70 ° C. and humidity of 93% for about 24 hours, and bubbles are generated. The image of the part measured by optical microscope (Olympus, EX-51, 30x magnification) was analyzed by Mountech's Mac-view software, and the ratio of the size of the bubble to the area to the area was measured (%).

Pressure-sensitive adhesive composition

One aspect of the present invention is a pressure-sensitive adhesive composition is a monomer mixture comprising a (meth) acrylate having a hydroxyl group and a comonomer, and a composition comprising nanoparticles, the nanoparticles comprise a silicone-based polymer, the average particle diameter is about 5 nm to about 800 nm.

Having hydroxyl groups ( MET Acrylic Copolymer monomer  mixture

The monomer mixture includes (meth) acrylates and comonomers having hydroxyl groups. The monomer mixture may be polymerized to form a (meth) acrylic copolymer having a hydroxyl group.

The (meth) acrylic monomer having a hydroxyl group is a (meth) acrylic acid ester having an alkyl group having 1 to 20 carbon atoms having at least one hydroxyl group, a (meth) acrylic acid ester having a cycloalkyl group having 5 to 20 carbon atoms having at least one hydroxyl group, Or a (meth) acrylic acid ester having an aryl group having 6 to 20 carbon atoms having at least one hydroxyl group.

The (meth) acrylate monomer having a hydroxyl group is, for example, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydrate It may be one or more of oxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, but is not necessarily limited thereto. In particular, by using an alkyl group-containing (meth) acrylic monomer having 1 to 5 carbon atoms having a hydroxyl group, there may be an effect of increasing the adhesion of the pressure-sensitive adhesive film.

In embodiments, the (meth) acrylate having a hydroxyl group has a (meth) acryl having a hydroxyl group having a glass transition temperature (Tg) of about -80 ° C to about -20 ° C, specifically about -60 ° C to about -35 ° C. Rate can be used. For example, 4-hydroxybutyl (meth) acrylate may be used, but is not necessarily limited thereto. In the above temperature range, the adhesive film has excellent viscoelastic properties at low temperature and room temperature.

The (meth) acrylate having a hydroxyl group may be included in about 15% to about 45% by weight, specifically about 25% to about 40% by weight of the monomer mixture. The haze of the pressure-sensitive adhesive film in the above range is low, there is an excellent adhesive force.

Comonomers are alkyl (meth) acrylate monomers, monomers with ethylene oxide, monomers with propylene oxide, monomers with amine groups, monomers with amide groups, monomers with alkoxy groups, monomers with phosphoric acid groups, monomers with sulfonic acid groups, phenyl groups It may include one or more of a monomer having a monomer and a silane group, but is not necessarily limited thereto.

The alkyl (meth) acrylate monomer may include an unsubstituted linear or branched alkyl (meth) acrylic acid ester having 1 to 20 carbon atoms. For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, iso-butyl (meth) acrylic Latex, pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate, ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (Meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate. Specifically, by using an alkyl (meth) acrylic monomer having 4 to 8 carbon atoms, there may be an effect of increasing the initial adhesive strength.

As the monomer having ethylene oxide, one or more (meth) acrylate monomers containing an ethylene oxide group (—CH ₂ CH ₂ O—) may be used. For example, polyethylene oxide monomethyl ether (meth) acrylate, polyethylene oxide monoethyl ether (meth) acrylate, polyethylene oxide monopropyl ether (meth) acrylate, polyethylene oxide monobutyl ether (meth) acrylate, polyethylene oxide mono Pentyl ether (meth) acrylate, polyethylene oxide dimethyl ether (meth) acrylate, polyethylene oxide diethyl ether (meth) acrylate, polyethylene oxide monoisopropyl ether (meth) acrylate, polyethylene oxide monoisobutyl ether (meth) Polyethylene oxide alkyl ether (meth) acrylates such as acrylate, polyethylene oxide monotertbutyl ether (meth) acrylate, but are not necessarily limited thereto.

The monomer having propylene oxide may be polypropylene oxide monomethyl ether (meth) acrylate, polypropylene oxide monoethyl ether (meth) acrylate, polypropylene oxide monopropyl ether (meth) acrylate, polypropylene oxide monobutyl ether ( Meth) acrylate, polypropylene oxide monopentyl ether (meth) acrylate, polypropylene oxide dimethyl ether (meth) acrylate, polypropylene oxide diethyl ether (meth) acrylate, polypropylene oxide monoisopropyl ether (meth) Polypropylene oxide alkyl ether (meth) acrylates such as acrylates, polypropylene oxide monoisobutyl ether (meth) acrylates, polypropylene oxide monotertbutyl ether (meth) acrylates, but are not necessarily limited thereto. Is no.

Monomer which has the said amino group is monomethylaminoethyl (meth) acrylate, monoethylaminoethyl (meth) acrylate, monomethylaminopropyl (meth) acrylate, monoethylaminopropyl (meth) acrylate, and dimethylaminoethyl Amino-group-containing (meth) acrylic-types, such as (meth) acrylate, diethylaminoethyl (meth) acrylate, N-tert- butylaminoethyl (meth) acrylate, and methacryloxyethyl trimethylammonium chloride (meth) acrylate It may be a monomer, but is not necessarily limited thereto.

The monomer having an amide group may be (meth) acrylamide, N-methylacrylamide, N-methylmethacrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N, N-methylene Amide group-containing (meth) acrylic monomers such as bis (meth) acrylamide and 2-hydroxyethylacrylamide may be used, but are not necessarily limited thereto.

Monomers having the alkoxy group include 2-methoxy ethyl (meth) acrylate, 2-methoxypropyl (meth) acrylate, 2-ethoxypropyl (meth) acrylate, 2-butoxypropyl (meth) acrylate, 2-methoxypentyl (meth) acrylate, 2-ethoxypentyl (meth) acrylate, 2-butoxyhexyl (meth) acrylate, 3-methoxypentyl (meth) acrylate, 3-ethoxypentyl ( Meth) acrylate, 3-butoxyhexyl (meth) acrylate, but is not necessarily limited thereto.

As a monomer which has the said phosphate group, 2-methacryloyl oxyethyl diphenyl phosphate (meth) acrylate, trimethacryloyl oxyethyl phosphate (meth) acrylate, triacryloyloxy ethyl phosphate (meth) acrylate It may be an acrylic monomer having a phosphoric acid group, such as, but is not necessarily limited thereto.

The monomer having a sulfonic acid group is an acrylic monomer having a sulfonic acid group such as sodium sulfopropyl (meth) acrylate, sodium 2-sulfoethyl (meth) acrylate, and sodium 2-acrylamido-2-methylpropane sulfonate. However, the present invention is not limited thereto.

The monomer having a phenyl group may be an acryl-based vinyl monomer having a phenyl group such as p-tert-butylphenyl (meth) acrylate and o-biphenyl (meth) acrylate, but is not necessarily limited thereto.

Monomers having the silane group include 2-acetoacetoxyethyl (meth) acrylate, vinyltrimethoxysilane, vinyltriethoxysilane, vinyl tris (β-methoxyethyl) silane, vinyltriacetylsilane and methacryloyl. It may be a vinyl monomer having a silane group such as oxypropyltrimethoxysilane, but is not necessarily limited thereto.

The comonomer may be included in about 55% to about 85% by weight, specifically about 60% to about 75% by weight of the monomer mixture. The adhesive film in the above range has an excellent adhesive strength and excellent reliability effect.

In another embodiment, the comonomer may use a glass transition temperature (Tg) of about -150 ℃ to about 0 ℃. Here, the glass transition temperature can be measured, for example, using TA Instrument's DSC Q20 for the homopolymer of each monomer to be measured. Specifically, the temperature is raised to about 100 ° C. at about 20 ° C./min for the homopolymer of each monomer, and then cooled to about −180 ° C. at the same rate, and then about 100 ° C. at about 10 ° C./min. After the data of the endothermic transition curve when the temperature is raised to, the inflection point of the endothermic transition curve is determined as the glass transition temperature. The comonomer having the glass transition temperature (Tg) of about -150 ° C to about 0 ° C may be used without limitation as long as it has a glass transition temperature (Tg) of about -150 ° C to about 0 ° C. Specifically, a monomer having a glass transition temperature (Tg) of about -150 ° C to about -20 ° C, and more specifically, a monomer having a glass transition temperature (Tg) of about -150 ° C to about -40 ° C.

In another embodiment, the comonomer is an alkyl (meth) acrylate monomer, a monomer having ethylene oxide, a monomer having propylene oxide, a monomer having an amine group, a monomer having an amide group, a monomer having an alkoxy group, a monomer having a phosphoric acid group, One or more of the monomer having a sulfonic acid group, the monomer having a phenyl group, and the monomer having a silane group may have a glass transition temperature (Tg) of about -150 ° C to about 0 ° C.

Such comonomers are, for example, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, iso-butyl acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethyl Alkyl (meth) acrylate monomers including hexyl acrylate, dodecyl (meth) acrylate, and the like; Polyethylene oxide monomethyl ether (meth) acrylate, polyethylene oxide monoethyl ether (meth) acrylate, polyethylene oxide monopropyl ether (meth) acrylate, polyethylene oxide monobutyl ether (meth) acrylate, polyethylene oxide monopentyl ether ( Contains alkylene oxide groups including meth) acrylate, polypropylene oxide monomethyl ether (meth) acrylate, polypropylene oxide monoethyl ether (meth) acrylate, polypropylene oxide monopropyl ether (meth) acrylate, and the like ( Meth) acrylate monomers; (Meth) acryl which has an amino group containing monomethylaminoethyl (meth) acrylate, monoethylaminoethyl (meth) acrylate, monomethylaminopropyl (meth) acrylate, monoethylaminopropyl (meth) acrylate, etc. Acrylate monomers; (Meth) acrylate monomers having an alkoxy group including 2-methoxy ethyl (meth) acrylate, 2-methoxypropyl (meth) acrylate, 2-ethoxypropyl (meth) acrylate, and the like; It may be one or more of (meth) acrylate monomers having a silane group including 2-acetoacetoxyethyl (meth) acrylate, vinyltrimethoxysilane, vinyltriethoxysilane, and the like.

In another embodiment, the monomer mixture forming the (meth) acrylic copolymer having a hydroxyl group may further include a monomer having a carboxyl group.

The monomer having a carboxyl group is (meth) acrylic acid, 2-carboxyethyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, 4-carboxybutyl (meth) acrylate, itaconic acid, crotonic acid, maleic acid, Fumaric acid and maleic anhydride, and the like, but are not necessarily limited thereto.

The monomer having a carboxyl group may include about 0.1% to about 10% by weight, specifically about 0.1% to about 7% by weight, more specifically about 0.1% to about 5% by weight of the monomer mixture. In the above range, the adhesive force of the adhesive film is high, and there is an excellent effect of reliability.

Nanoparticles

Since the adhesive composition includes nanoparticles, the adhesive film has excellent low temperature and / or room temperature viscoelasticity, and has a crosslinked structure to stably exhibit high temperature viscoelasticity of the adhesive film. In an embodiment, the nanoparticles may form a chemical bond with the (meth) acrylic copolymer having the hydroxyl group.

Specifically, by applying a nanoparticle having a specific average particle diameter with a small difference in refractive index and a (meth) acrylic copolymer having a hydroxyl group, it is possible to obtain an adhesive film having excellent transparency despite the inclusion of nanoparticles.

The nanoparticles have an average particle diameter of about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, 700, 710, 720, 730, 740, 750, 760, 770, 780, 790 or 800 nm. In addition, the nanoparticles may have an average particle diameter in a range of at least one of the above values and at most one of the above values. For example, the nanoparticles may have an average particle diameter of about 5 nm to about 800 nm, specifically about 5 nm to about 700 nm, and more specifically about 10 nm to about 400 nm. In the above range, the aggregation of nanoparticles can be prevented and the transparency is excellent.

The nanoparticles have a refractive index difference of about 0.05 or less, specifically about 0 or more and about 0.05 or less, specifically about 0 or more and about 0.03 or less, and more specifically, about a refractive index difference with the (meth) acrylic copolymer having a hydroxyl group formed from the adhesive mixture. It may be from 0 to about 0.02. In the above range, the transparency of the pressure-sensitive adhesive film is excellent.

The nanoparticles have a core-shell structure, and the glass transition temperature of the core and the shell may satisfy the following Equation 1.

[Equation 1]

Tg (c) <Tg (s)

(In Formula 1, Tg (c) is the glass transition temperature (° C.) of the core, and Tg (s) is the glass transition temperature (° C.) of the shell.)

Specifically, the glass transition temperature of the core may be about -200 ℃ to about -40 ℃, specifically about -200 ℃ to about -80 ℃, more specifically about -200 ℃ to about -90 ℃. In the above range, it is possible to realize a storage modulus value required at low temperature (about -20 ° C), and excellent low temperature and / or room temperature viscoelastic properties.

The nanoparticles may include a silicone-based polymer, and the silicone-based polymer may have the core-shell structure.

Specifically, the core of the silicone-based polymer may be polysiloxane having a glass transition temperature of the nanoparticle core or a mixture thereof. The polysiloxane can be, for example, an organosiloxane (co) polymer. The organosiloxane (co) polymer may be one which is not crosslinked, or a crosslinked (co) polymer may be used. Crosslinked organosiloxane (co) polymers can be used for impact resistance and colorability. This is a crosslinked organosiloxane, specifically, crosslinked dimethylsiloxane, methylphenylsiloxane, diphenylsiloxane or a mixture of two or more thereof may be used. The refractive index of about 1.41 to about 1.50 can be adjusted by using a form in which two or more organosiloxanes are copolymerized.

The crosslinking state of the organosiloxane (co) polymer can be judged with the degree to be dissolved by various organic solvents. The deeper the crosslinking state, the smaller the degree of dissolution by the solvent. Acetone or toluene may be used as a solvent for determining the crosslinking state. Specifically, the organosiloxane (co) polymer may have a portion which is not dissolved by acetone or toluene. The insoluble component of the organosiloxane copolymer to toluene may be about 30% or more.

Additionally, the organosiloxane (co) polymer may further include an alkylacrylate crosspolymer. As the alkyl acrylate crosspolymer, methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate and the like can be used. For example, n-butyl acrylate or 2-ethylhexyl acrylate having a low glass transition temperature can be used.

Specifically, the silicone-based polymer may have a glass transition temperature of about 15 ° C. to about 200 ° C., specifically about 15 ° C. to about 180 ° C., more specifically about 15 ° C. to about 150 ° C. There is an advantage in that the fairness of the particles in the above range.

The shell may comprise a poly (meth) acrylate having the glass transition temperature. For example, polymethyl acrylate, polymethyl methacrylate (PMMA), polyethyl methacrylate, polypropyl methacrylate, polybutyl methacrylate, polyisopropyl methacrylate, polyisobutyl methacrylate, And may include, but are not necessarily limited to, polycyclohexyl methacrylate, polyphenyl methacrylate, and polybenzyl methacrylate. Specifically, it may include polymethyl methacrylate.

The shell may comprise two or more layers. In this case, the outermost layer of the nanoparticles may include polyalkyl (meth) acrylate having a glass transition temperature (Tg) of about 15 ° C to about 200 ° C.

In one embodiment, the nanoparticles included in the pressure-sensitive adhesive composition may be used in a polymerized state with the monomer mixture when preparing the (meth) acrylic copolymer having a hydroxyl group. In this case, the nanoparticles may be used in a state contained in the (meth) acrylic copolymer having a hydroxyl group.

In another embodiment, the pressure-sensitive adhesive composition may include nanoparticles together with a (meth) acrylic copolymer having a hydroxyl group in an already prepared state. In this case, the nanoparticles may be included in the pressure-sensitive adhesive composition in a state separate from the (meth) acrylic copolymer having a hydroxyl group.

The nanoparticles are about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, based on 100 parts by weight of the monomer mixture including a (meth) acrylate having a hydroxyl group and a comonomer. 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5 or 20 parts by weight. In addition, the nanoparticles may be in the range of about one or more of the above values and about one or less of the above values based on 100 parts by weight of the monomer mixture forming the (meth) acrylic copolymer having a hydroxyl group. For example, the nanoparticles are about 0.1 parts by weight to about 20 parts by weight, specifically about 0.1 parts by weight to about 18 parts by weight, more specifically, based on 100 parts by weight of the monomer mixture forming the (meth) acrylic copolymer having a hydroxyl group. About 0.1 parts by weight to about 15 parts by weight. In the above range, it is possible to balance viscoelasticity and storage modulus and recovery force.

The weight ratio of the core and the shell of the nanoparticles may be about 1: 1 to about 9: 1, specifically about 1: 1 to about 8: 1, more specifically about 1.5: 1 to about 8: 1. In the above range, the viscoelastic properties are maintained in a wide range, and the compatibility and recovery force are excellent.

The pressure-sensitive adhesive composition may further include one or more of an initiator and a crosslinking agent.

Initiator

The initiator may use a photopolymerization initiator or a thermal polymerization initiator. The initiator may use the same or different initiator as the initiator used in preparing the prepolymer to partially polymerize.

As said photoinitiator, as long as it can induce the polymerization reaction of the radically polymerizable compound mentioned above in the hardening process by light irradiation etc., and can implement | achieve a 2nd crosslinked structure, any can be used. For example, a benzoin type, a hydroxy ketone type, an amino ketone type, or a phosphine oxide type photoinitiator etc. can be used, Specifically, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether , Benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylanino acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2 -Hydroxy-2-methyl-1-phenylpropane-1one, 1-hydroxycyclohexylphenylketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propane-1- On, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4-nonsidiethylaminobenzophenone, dichlorobenzophenone, 2 -Methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4- Dimethyl Tea Ozantone, 2,4-diethyl thioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, p-dimethylamino benzoic acid ester, oligo [2-hydroxy-2-methyl-1- [4- (1-methylvinyl) Phenyl] propanone], 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and the like. In the present application, one or more of the above may be used, but is not limited thereto.

The type of the thermal polymerization initiator is not particularly limited as long as it can induce a polymerization reaction of the polymerizable compound to implement the second crosslinked structure. For example, an azo compound, a peroxide compound, or a redox system is used. Conventional initiators such as compounds can be used. Examples of the azo compound in the above are 2,2-azobis (2-methylbutyronitrile), 2,2-triazobis (isobutyronitrile), 2,2-triazobis (2,4-dimethyl Valeronitrile), 2,2-nitazobis-2-hydroxymethylpropionitrile, dimethyl-2,2-methylazobis (2-methylpropionate) and 2,2-piazobis (4- Methoxy-2,4-dimethylvaleronitrile) and the like, and examples of the peroxide-based compound include inorganic peroxides such as potassium peroxide, ammonium persulfate or hydrogen peroxide; Or diacyl peroxide, peroxy dicarbonate, peroxy ester, tetramethylbutylperoxy neodecanoate, bis (4-butylcyclohexyl) peroxydicarbonate, di (2-ethylhexyl) peroxy carbonate, butylper Oxy neodecanoate, dipropyl peroxy dicarbonate, diisopropyl peroxy dicarbonate, diethoxyethyl peroxy dicarbonate, diethoxyhexyl peroxy dicarbonate, hexyl peroxy dicarbonate, dimethoxybutyl peroxy dicarbonate , Bis (3-methoxy-3-methoxybutyl) peroxy dicarbonate, dibutyl peroxy dicarbonate, dicetyl peroxy dicarbonate, dimyristyl peroxy dicarbonate, 1,1 , 3,3-tetramethylbutyl peroxypivalate, hexyl peroxy pivalate, butyl peroxy pivalate, trimethyl hexanoyl peroxide, dimethyl hydroxybutyl peroxy Odecanoate, amyl peroxyneodecanoate, butyl peroxyneodecanoate, t-butylperoxy neoheptanoate, amylperoxy pivalate, t-butylperoxy pivalate, t-amyl Organic peroxides such as peroxy-2-ethylhexanoate, lauryl peroxide, dilauuroyl peroxide, didecanoyl peroxide, benzoyl peroxide or dibenzoyl peroxide, and the like. Examples of the compound include, but are not limited to, a mixture using a peroxide compound and a reducing agent in combination. In the present application, one kind or a mixture of two or more kinds of the azo-based, peroxide-based or redox-based compounds may be used.

The initiator may be included in an amount of about 0.01 to about 5 parts by weight, specifically about 0.005 parts by weight to about 3 parts by weight, more specifically about 0.1 part by weight to about 1 part by weight, based on 100 parts by weight of the monomer mixture. In the above range, the curing reaction may proceed completely, and the residual amount of initiator may remain to prevent the transmittance of the adhesive film from decreasing, and also may lower bubble generation, and may have excellent reactivity.

Crosslinking agent

Crosslinking agents are polyfunctional (meth) acrylates, for example 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentylglycol di (meth) acrylate, Polyethylene glycol di (meth) acrylate, neopentylglycol adipate di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylic Ethylene Oxide Modified Di (meth) acrylate, Di (meth) acryloxyethyl Isocyanurate, Allylated Cyclohexyl Di (meth) acrylate, Tricyclodecanedimethanol (meth) acrylate, Dimethylol Dish Clopentane di (meth) acrylate, ethylene oxide modified hexahydrophthalic acid di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, neopentylglycol modified trimeth Bifunctional acrylics such as ylpropane di (meth) acrylate, adamantane di (meth) acrylate or 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene Rate; Trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide Trifunctional acrylates such as modified trimethylolpropane tri (meth) acrylate, trifunctional urethane (meth) acrylate or tris (meth) acryloxyethyl isocyanurate; Tetrafunctional acrylates such as diglycerin tetra (meth) acrylate or pentaerythritol tetra (meth) acrylate; 5-functional acrylates, such as dipentaerythritol penta (meth) acrylate; And dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate or urethane (meth) acrylate (ex. Isocyanate monomers and trimethylolpropane tri (meth) acrylate 6-functional acrylates such as reactants, etc., but are not limited thereto.They may be used alone or in combination of two or more. Specifically, the crosslinking agent may be a polyfunctional ( By using meth) acrylate, there exists an effect which has the outstanding durability reliability.

The crosslinking agent may be included in an amount of about 0.01 to about 5 parts by weight, specifically about 0.03 to about 3 parts by weight, specifically about 0.1 to about 0.3 parts by weight, based on 100 parts by weight of the monomer mixture. In the above range there is an effect of increasing the adhesive strength and reliability of the adhesive film.

In another embodiment, the pressure-sensitive adhesive composition may further include a silane coupling agent.

Silane Coupling agent

The silane coupling agent may further include a siloxane-based or epoxy-based silane coupling agent, but is not limited thereto. The silane coupling agent is about 0.01 parts by weight to about 5 parts by weight, specifically about 0.01 parts by weight to about 2 parts by weight, and more specifically about 0.01 to about 0.5 parts by weight based on 100 parts by weight of the (meth) acrylic copolymer having a hydroxyl group. It can be included as a wealth. There is an effect of increasing the reliability of the adhesive film in the above range.

additive

The pressure-sensitive adhesive composition may optionally include a curing accelerator, an ionic liquid, a lithium salt, an inorganic filler, a softener, a molecular weight regulator, an antioxidant, an antioxidant, a stabilizer, a tackifying resin, a modified resin (polyol resin, a phenol resin, an acrylic resin, a polyester resin). , Polyolefin resins, epoxy resins, epoxidized polybutadiene resins, etc.), leveling agents, antifoaming agents, plasticizers, dyes, pigments (colored pigments, sieving pigments, etc.), treatment agents, sunscreen agents, fluorescent brighteners, dispersants, thermal stabilizers, Conventional additives such as light stabilizers, ultraviolet absorbers, antistatic agents, flocculants, lubricants and solvents may be further included.

The pressure-sensitive adhesive composition may further include a non-curable compound. The pressure-sensitive adhesive composition does not include a solvent, the viscosity of 25 ℃ can be about 300 cPs to about 50,000 cPs. Since an adhesive composition does not contain a solvent, foaming can be reduced and reliability can be improved. The pressure-sensitive adhesive composition in the above range has the effect of obtaining excellent coating properties and thickness uniformity.

Adhesive film

The pressure-sensitive adhesive film according to one embodiment of the present invention may be formed of the pressure-sensitive adhesive composition. The adhesive film may include a (meth) acrylic copolymer having a hydroxyl group polymerized from a monomer mixture including a (meth) acrylate having a hydroxyl group and a comonomer.

Specifically, after the initiator is added to the monomer mixture and partially polymerized to prepare a syrup including a (meth) acrylic copolymer (prepolymer) having a hydroxyl group, nanoparticles may be added to the syrup to prepare an adhesive composition. Or partial polymerization by adding an initiator to a mixture comprising a (meth) acrylate monomer having a hydroxyl group, a comonomer (e.g., a comonomer having a glass transition temperature (Tg) of about -150 ° C to about 0 ° C) and nanoparticles Thus, a syrup containing a (meth) acrylic copolymer (prepolymer) having a hydroxyl group can be produced.

The weight average molecular weight of the (meth) acrylic copolymer having a partially polymerized hydroxyl group may be about 500,000 g / mol to about 3 million g / mol, specifically about 1 million g / mol to about 2.8 million g / mol have. In the above range can increase the durability of the adhesive film.

The pressure-sensitive adhesive film is prepared by mixing an initiator and / or a crosslinking agent with a syrup including the (meth) acrylic copolymer having a partially polymerized hydroxyl group to prepare a pressure-sensitive adhesive composition, and coating and coating the pressure-sensitive adhesive composition with UV curing. It can manufacture.

In an embodiment, the pressure-sensitive adhesive film is partially polymerized by mixing a monomer mixture, nanoparticles and a photopolymerization initiator forming a (meth) acrylic copolymer having a hydroxyl group, and adding an additional photopolymerization initiator and / or a crosslinking agent to the partially polymerized syrup. The pressure-sensitive adhesive composition prepared by coating on a release film may be prepared by curing. Curing was carried out at low pressure lamps in anoxic conditions with an irradiation dose of about 400 mJ / cm at a wavelength of about 300 nm to about 400 nm.² To about 30,000 mJ / cm²May include investigation. The coating thickness is not particularly limited and may be about 10 μm to about 2 mm, specifically about 20 μm to about 1.5 mm.

The adhesive film may be used as an OCA film, or may be formed on an optical film and used as an adhesive optical film. Examples of the optical film may include a polarizing plate. The polarizing plate may include a polarizer, a protective film formed on the polarizer, and further include a hard coating layer and an antireflection layer.

The adhesive film may have a thickness of about 10 μm to about 2 mm, specifically about 50 μm to about 1.5 mm. It can be used in the optical display device in the above range.

The adhesive film has a glass transition temperature (Tg) of about 0 ° C. or less, specifically about -150, -145, -140, -135, -130, -125, -120, -115, -110, -105,- 100, -95, -90, -85, -80, -75, -70, -65, -60, -55, -50, -45, -40, -35, -30, -25, -20, Can be -15, -10, -5 or 0 ° C. In addition, the adhesive film may have a glass transition temperature (Tg) of about one or more of the above values and about one or less of the above values. For example, the adhesive film may have a glass transition temperature (Tg) of about -150 ° C to about 0 ° C, specifically about -150 ° C to about -20 ° C, and more specifically about -150 ° C to about -30 ° C. have. In the above range, the adhesive film is excellent in viscoelastic properties at low and normal temperatures.

The adhesive film has a storage modulus of about 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600 at 80 ° C. , 650, 700, 750, 800, 850, 900, 950 or 1000 KPa. In addition, the adhesive film may have a storage modulus at 80 ° C. in the range of about one or more of the above values and about one or less of the above values. For example, the adhesive film may have a storage modulus of about 10 KPa to about 1,000 KPa, specifically about 10 KPa to about 300 KPa, and more specifically about 10 KPa to about 100 KPa at 80 ° C. In the above range, the adhesive film exhibits viscoelastic properties even at a high temperature, and even when frequently folded at a high temperature, the adhesive film does not fall off from the adhesive and can prevent the adhesive film from overflowing. Excellent recovery power.

The adhesive film has a storage modulus of about 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600 at 25 ° C. , 650, 700, 750, 800, 850, 900, 950 or 1000 KPa. In addition, the pressure-sensitive adhesive film may have a storage modulus at 25 ° C. of about one or more of the above values and about one or less of the above values. For example, the adhesive film has a storage modulus at 25 ° C. of about 10 KPa to about 1000 KPa, specifically about 10 KPa to about 500 KPa, more specifically about 10 KPa to about 300 KPa, even more specifically about 10 KPa to about It can be 150 KPa. In the above range, the viscoelastic characteristics of the pressure-sensitive adhesive film is expressed at room temperature, and has an advantage of excellent recovery force.

The adhesive film has a storage modulus of about 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, at -20 ° C. It can be 600, 650, 700, 750, 800, 850, 900, 950 or 1000 KPa. In addition, the adhesive film may have a storage modulus at −20 ° C. of about one or more of the above values and about one or less of the above values. For example, the adhesive film has a storage modulus at -20 ° C of about 10 KPa to about 1000 KPa, specifically about 10 KPa to about 700 KPa, more specifically about 10 KPa to about 500 KPa, even more specifically about 10 KPa to It can be about 200 KPa. In the above range, when the adhesive film is used in the flexible device at a low temperature, it is flexible and there is no whitening phenomenon, there is an advantage that can be used for optical materials.

In addition, the ratio of the storage modulus at 80 ° C. to the storage modulus at −20 ° C. of the adhesive film is about 1: 1 to about 1:20, specifically about 1: 1 to about 1:15, and more specifically about 1: 1 to about 1: 1. It can be about 1: 10. In the above range, the adhesive film does not fall off the adhesive strength between the adhesives in a wide temperature range (about -20 ℃ to 80 ℃), the adhesive film can be used in a flexible (flexible) optical member.

The adhesive film may have a haze of about 4% or less, specifically about 3% or less, and more specifically about 2% or less at a thickness of 100 μm. In the above range, excellent transparency is exhibited when the adhesive film is used in an optical display device.

The adhesive film may have a haze of about 5% or less, specifically about 3% or less, and more specifically about 2% or less after stretching about 200% at a thickness of 100 μm. In the above range, the adhesive film exhibits excellent transparency when used in a display.

The adhesive film may have a recovery force of about 30% to about 98%, specifically about 40% to about 95%, and more specifically about 40% to about 90% at a thickness of 100 μm. In the above range, the adhesive film can be applied to a flexible optical display device, and the service life is also long.

[Equation 2]

Recovery Force (%) = (1- (X _f / X ₀ )) × 100

(Equation 2, when the both ends of the PET (polyethylene terephthalate) film (thickness: about 75㎛) of horizontal × vertical (about 50 mm × about 20 mm), respectively called the first end and the second end, The end portions of each of the two PET films are adhered to each other by an X-length (about 20 mm × about 20 mm) adhesive film, and the first end / adhesive film of the PET film (width × length, about 20 mm × about 20 mm) A test piece was prepared in the order of the second end of the PET film, the jig was fixed to both ends of the PET film, one jig was fixed, and the other jig was pulled at a speed of about 300 mm / min. After reaching the length (about 10 times the thickness, X ₀ ) of about 1000% of the thickness (unit: ㎛) of the pressure-sensitive adhesive film is maintained for about 10 seconds, and restored at the same speed as the pulled speed (about 300 mm / min Length of the adhesive film when the pressure of about 0 kPa is applied to the adhesive film is X _f (unit: μm)).

When the adhesive film (about 13 cm width × about 3 cm length, thickness about 100 μm) is aged at a temperature of about 70 ° C. and a humidity of about 93% for about 24 hours, the bubble generation area (%) is about 0%. Can be. In the above range, the fall with the adherend does not occur even at high temperature and high humidity.

The “bubble generating area” is a PET having a thickness of about 50 μm on one side of an adhesive film (about 13 cm × about 3 cm, thickness of about 100 μm) and PET having a thickness of about 100 μm on the back side of the adhesive film. The pressure-sensitive adhesive film is bent in a direction of 50 μm PET so that the horizontal length of the pressure-sensitive adhesive film is about 1/2 between the parallel molds spaced about 1 cm, and aged at a temperature of about 70 ° C. and a humidity of about 93% for about 24 hours. The image measured by the optical microscope (Olympus, EX-51) was analyzed by Mountech's Mac-view software, and the ratio of the size of the bubble to the area to the area was measured (%).

The adhesive film was cut to a thickness of about 100 μm, about 5 cm × about 5 cm, and rolled so as to adhere tightly to each other, and then fixed at both ends to TA (TA.XT_Plus Texture Analyzer (Stable Micro System)). In the case of stretching at a speed of 300 mm / min, the length of the break point of the adhesive film is about 800% to about 2,000%, specifically about 800% to about 1,800%, more specifically about 900% compared to the length before stretching. It may be from about 1,800% In the above range, the adhesive film is maintained in viscoelasticity over a wide temperature range, and excellent in reliability.

In order to increase the peel strength, the pressure-sensitive adhesive film is surface-treated in advance on the surface to which the pressure-sensitive adhesive composition is applied, for example, about 150 mJ / cm ² The corona pretreatment step may be followed. Specifically, when the corona pretreatment step is carried out, the peeling strength of the adhesive film T-peel at 25 ° C. and 60 ° C. may be further increased. For example, the corona pretreatment may be performed by using a corona treatment (Now plasma) to treat the surface to be bonded (eg, PET film) about twice with a dose of about 78 doses, but is not necessarily limited thereto. .

The adhesive film has a thickness of 100 μm, and the T-peel peeling strength of the corona-treated PET film at room temperature (25 ° C.) is about 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, It can be 3100, 3200, 3300, 3400, 3500, 3600, 3700, 3800, 3900 or 4000 gf / in. In addition, the pressure-sensitive adhesive film has a thickness of 100 μm, the T-peel peeling strength of the corona treated PET film at room temperature (25 ° C.) of about one or more of the above values and about one or less of the above values Can be For example, the pressure-sensitive adhesive film has a thickness of 100 μm, and the T-peel peeling strength of the corona treated PET film at room temperature (25 ° C.) is about 400 gf / in to about 4,000 gf / in, specifically, For example, about 500 gf / in to about 4,000 gf / in, and more specifically, about 700 gf / in to about 3,500 gf / in. Within the above ranges, the adhesion and reliability at room temperature are excellent.

In addition, the adhesive film has a T-peel peel strength of about 200, 250, 300, 350, 400, 450, 500, 550, 600 for a corona treated PET film at 60 ° C. at a thickness of 100 μm. , 650, 700, 750, 800, 850, 900, 950, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700 , 2800, 2900 or 3000 gf / in. In addition, the adhesive film has a thickness of 100 μm, the T-peel peel strength of the corona treated PET film at 60 ° C. may be in the range of at least one of the above values and at most one of the above values. have. For example, the adhesive film has a T-peel peel strength of about 200 gf / in to about 3,000 gf / in, specifically about 500, at a thickness of 100 μm for a corona treated PET film at 60 ° C. gf / in to about 2,000 gf / in, more specifically about 500 gf / in to about 1,500 gf / in. In the above range, even when the adhesive film at high temperature has a curvature shape, the adhesive force and reliability are excellent.

T-peel peel strength of the adhesive film is measured as follows. Corona of PET film with corona treatment of horizontal × length × thickness (about 150 mm × about 25 mm × about 75 μm) on both sides of the adhesive film of about 100 mm × 25 mm × 100 μm (width × length × thickness) Each pretreated side is laminated and autoclaved for about 1000 seconds at a pressure of about 3.5 bar and about 50 ° C. and fixed in a TA.XT_Plus Texture Analyzer (Stable Micro System). At 25 ° C. or 60 ° C., one PET film is fixed and the other PET film is pulled at a rate of about 50 mm / min to measure the T-peel peel strength for the PET film. Corona pretreatment of the PET film may be, for example, using a corona treatment (Now plasma) to treat the PET film twice (total dose: about 156 doses) at a dose of about 78 doses. It is not.

Display member

Another aspect of the invention relates to a display member.

The display member is an optical film; And the adhesive film attached to one side or both sides of the optical film.

1 is a cross-sectional view of a display member of one embodiment of the present invention.

Referring to FIG. 1, the display member may include an optical film 40 and an adhesive layer or an adhesive film formed on one surface of the optical film 40. In FIG. 1, 200 may be an adhesive layer or an adhesive film.

In one embodiment, the display member is an optical film 40; And an adhesive layer 200 formed on one or both surfaces of the optical film 40.

The pressure-sensitive adhesive layer may be formed of the pressure-sensitive adhesive composition of the present invention. Specifically, the pressure-sensitive adhesive composition prepared by mixing and polymerizing a monomer mixture, a nanoparticle, and a photopolymerization initiator to form a (meth) acrylic copolymer having a hydroxyl group, and adding an additional photopolymerization initiator to the polymer may be applied to the optical film or An adhesive layer can be formed by the method of coating. The pressure-sensitive adhesive layer may further include a drying process.

In another embodiment, the display member comprises an optical film 40; And it may include a pressure-sensitive adhesive film 200 of the present invention formed on one side or both sides of the optical film.

The optical film may include a touch panel, a window, a polarizing plate, a color filter, a retardation film, an elliptical polarizing film, a reflective film, an antireflection film, a compensation film, a brightness enhancement film, an alignment film, a light diffusion film, a glass scattering prevention film, and a surface protection film. , OLED device barrier layer, plastic LCD substrate, film with indium tin oxide (ITO), film with fluorinated tin oxide (FTO), film with aluminum dopped zinc oxide (AZO), film with carbon nanotube (CNT), Ag nanowire ( and a transparent electrode film such as a nanowire-containing film or a graphene-containing film. The manufacturing method of the optical film can be easily manufactured by those skilled in the art to which the present invention pertains.

For example, the display member may be formed by attaching a touch panel to a window or an optical film using the adhesive film. Or it can also be applied as a pressure-sensitive adhesive film to a conventional polarizing film as in the prior art. In more detail, the display device may include a capacitive mobile phone as an optical display device.

In an embodiment, the display member may include a first adhesive film on an optical device portion, a touch function portion on the first adhesive film, a second adhesive film on the touch function portion, and a window film on the second adhesive film in sequence. It may be stacked.

The optical device unit may include an OLED, an LED, or a light source, and the first adhesive film or the second adhesive film may be an adhesive film of the present invention. The touch function unit may be a touch panel, but is not limited thereto.

In addition, the window film may be formed of an optically transparent and flexible resin. For example, the window film may include a base layer and a hard coating layer.

The base layer is a poly (meth) containing a polyester resin such as polyethylene terephthalate polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, polycarbonate resin, polyimide resin, polystyrene resin, polymethyl methacrylate, and the like. It may be made of any one or more of the acrylate resin.

The hard coating layer may have a strength of about 6H or more when tested for pencil hardness, and specifically, may be formed of a siloxane resin.

In another embodiment, the display member may include a liquid crystal panel in which polarizers are stacked on both sides of the LCD cell, a double sided adhesive tape (DAT) for adhering a functional film (eg, an antireflective film) to each other, and a touch panel portion formed on the functional film. Can be. The touch panel unit includes a first adhesive film, a first transparent electrode film, a second adhesive film, and a second transparent electrode film laminated on the first adhesive film. An electrode and an overcoating layer for the electrode are formed on the second transparent electrode film, and the third adhesive film and the window glass are sequentially stacked on the overcoating layer. The air gap can be removed when laminating.

Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. However, this is presented as a preferred example of the present invention and in no sense can be construed as limiting the present invention.

Details that are not described herein will be omitted since those skilled in the art can sufficiently infer technically.

Example

(A) monomer mixture

(a1) 2-ethylhexyl acrylate (EHA) was used.

(a2) 4-hydroxybutyl acrylate (HBA) was used.

(B) nanoparticles

(b1) 99.5 g of dimethylsiloxane-diphenylsiloxane crosslinked copolymer having a refractive index of 1.43, an average particle diameter of 170 nm, and a toluene insoluble content of 41%, 127.2 g of n-butylacrylate, and 2.4 g of triallyl isocyanurate; Mixing in. A silicone mixture was prepared in which 1.4 g of sodium dodecylbenzene sulfate was dispersed in 760 g of ion-exchanged water. 2.4 g of potassium persulfate was added while maintaining the temperature of the mixed solution at 75 ° C., and the polymerization was carried out for 4 hours. Thereafter, 0.7 g of potassium persulfate was further added, and a solution of 64.8 g of methyl methacrylate and 7.25 g of methyl acrylate was added dropwise for 15 minutes. And the reaction proceeds for 4 hours at 75 ° C and cooled to room temperature. (Reaction conversion rate: 97.4%) The final reaction solution and 1.5% MgSO ₄ aqueous solution were mixed at 75 ° C., washed with water and dried to prepare nanoparticles, and their presence was confirmed. The prepared nanoparticles had a refractive index (N _B ) of 1.45, an average particle diameter of 173 nm, and a weight ratio of the core and the shell to 2.36: 1.

(b2) 120 g of dimethylsiloxane-diphenylsiloxane crosslinked copolymer having a refractive index of 1.45 and an average particle diameter of 210 nm and a toluene insoluble content of 60%, 127.2 g of 2-ethylhexyl acrylate, and 2.4 g of triallyl isocyanurate Mix at room temperature. A silicone mixture was prepared in which 2.8 g of sodium dodecylbenzene sulfate was dispersed in 980 g of ion-exchanged water. 2.4 g of potassium persulfate was added while maintaining the temperature of the mixed solution at 75 ° C., and the polymerization was carried out for 4 hours. Thereafter, 0.7 g of potassium persulfate was further added, and a solution of 64.8 g of methyl methacrylate and 7.25 g of methyl acrylate was added dropwise for 15 minutes. After the reaction proceeds for 4 hours at 75 ℃ and cooled to room temperature. (Reaction conversion rate: 95.8%) The final reaction solution and 1.5% MgSO ₄ aqueous solution were mixed at 75 ° C., washed with water and dried to prepare nanoparticles, and their presence was confirmed. The prepared nanoparticles had a refractive index (N _B ) of 1.46, an average particle diameter of 214 nm, and a weight ratio of the core and the shell to 2.79: 1.

(C) radical type photoinitiator

(c1) Igacure 651 (2,2-dimethoxy-2-phenylacetophenone) manufactured by BASF was used.

(c2) Igacure 184 (1-hydroxy-cyclohexyl-phenyl-ketone) manufactured by BASF was used.

(D) Additive (coupling agent): KBM-403 manufactured by Shin-Etsu was used.

Example  One

2.5 parts by weight of nanoparticles (b1) and photopolymerization initiator (c1) based on 100 parts by weight of the monomer mixture comprising 60% by weight of 2-ethylhexyl acrylate (a1), 40% by weight of 4-hydroxybutyl acrylate (a2) (Irgacure 651) 0.005 parts by weight was mixed well in a glass vessel. The dissolved oxygen in the glass container was replaced with nitrogen gas, and the mixture was partially polymerized by irradiating with ultraviolet rays using a low pressure lamp (50 mw / cm ² , BL Lamp manufactured by Sankyo), thereby producing a (meth) acrylic type having a hydroxyl group. A syrup made up of a copolymer (prepolymer), nanoparticles and unpolymerized monomer mixture was prepared. An adhesive composition (viscosity: 1500 cPs) was prepared by adding 0.35 parts by weight of an additional photopolymerization initiator (c2) (Irgacure 184) to the syrup.

The resulting pressure-sensitive adhesive composition was coated on a polyester film (release film, polyethylene terephthalate film, 50 μm thick) to form an adhesive film having a thickness of 100 μm. Then, after covering the release film of a thickness of 75 ㎛ on the top, and irradiated with a low pressure lamp (50mw / cm ² , BL Lamp manufactured by Sankyo) for 6 minutes on both sides to obtain a transparent adhesive sheet. The glass transition temperature (Tg) of the pressure-sensitive adhesive film was -38.6 ° C.

Example  2 to 5 and Comparative example  One

Except for changing the content of each component in Example 1 as in Table 1 was carried out in the same manner as in Example 1 to prepare a transparent adhesive sheet.

Physical properties of Table 1 below were evaluated for the pressure-sensitive adhesive films prepared in Examples and Comparative Examples, and the results are shown in Table 1 below.

Property evaluation method

(1) Glass transition temperature (Tg, ° C.): A sample of 15 mg (on 6 mm Al Pan) was made on the pressure-sensitive adhesive films of Examples and Comparative Examples, and the temperature rising rate of 20 ° C./min in a nitrogen atmosphere (50 mL / min) was obtained. The glass transition temperature (Tg) of the pressure-sensitive adhesive film was raised to 100 ° C., cooled to -80 ° C. at the same rate (first heating condition (1st run)), and then heated up to 100 ° C. at a temperature rising rate of 10 ° C./min. Was measured.

 (2) Storage modulus: ARES (Anton Paar MCR-501), a dynamic viscoelasticity measuring device, was used to measure viscoelasticity under auto strain conditions at shear rate of 1 rad / sec and strain of 1%. After removing the release film, the prepared pressure-sensitive adhesive film was laminated to a thickness of 1 mm, the laminate was punched out using a puncher having a diameter of 8 mm, and used as a specimen. Measurements were carried out at a rate of temperature rise of 5 ° C./min in the temperature range of −60 ° C. to 90 ° C., and elastic modulus was recorded at −20 ° C., 25 ° C., and 80 ° C.

 (3) T-peel peel strength: Corona treatment twice (total dose) on a PET film of width × length × thickness (150 mm × 25 mm × 75 μm) while discharging at a dose of 78 doses using a corona treatment machine. : 156 dose). The adhesive film sample was obtained by the magnitude | size of 100 mm x 25 mm x 100 micrometer (width X length X thickness) from the adhesive sheet of an Example and a comparative example. The corona treated surface of the PET film was laminated on both surfaces of the adhesive film sample, thereby preparing the specimen shown in FIG. The specimens were autoclaved at pressure of 3.5 bar at 50 ° C. for 1000 seconds and the specimens were fixed in a TA.XT_Plus Texture Analyzer (Stable Micro System). Referring to (b) of FIG. 2, using a TA.XT_Plus Texture Analyzer, one PET film was fixed at 25 ° C. and the other PET film was pulled at a rate of 50 mm / min to remove T-Peel at 25 ° C. Intensity was measured. (See Figure 2 (b))

In addition, using a TA.XT_Plus Texture Analyzer, one PET film was fixed at 60 ° C., and the other PET film was pulled at a rate of 50 mm / min to measure T-Peel peel strength at 60 ° C.

(4) Haze: Haze meter (Nippon Denshoku company model NDH 5000) equipment was used. At 100 μm thickness according to American Society for Testing and Measurement (ASTM) Test Method D 1003-95 (“Standard Test for Haze and Luminous Transmittance of Transparent Plastic”). Haze was measured.

(5) Haze after 200% stretching: Fix both ends of the sample (5 cm × 5 cm, thickness 100 μm) of the prepared pressure-sensitive adhesive film on both sides of the horizontal tensile tester, remove the release film on both sides, 200% in the longitudinal direction In the stretched state (two times the initial length, the state of the sample is 10 cm), the stretched specimen was prepared by bonding a pressure-sensitive adhesive film passed through a 2 kg roller with a glass plate on the bottom, a release film on the top. And after removing the upper release film, the haze was measured by the same method as the haze measurement method.

(6) Recovery force: When the both ends of the PET (polyethylene terephthalate) film (thickness: 75 µm) of width x length (50 mm x 20 mm) are called first and second ends, respectively, width x length ( 20 mm x 20 mm) adhesive film to adhere the end portions of each of the two PET films to each other, adhered in the order of the first end of the PET film / adhesive film / the second end of the PET film, PET film and adhesive film The contact area of the liver is measured with a specimen that is horizontal x vertical (20 mm x 20 mm). Referring to Figure 3 (a), (b), referring to Figure 3 (a), at room temperature (25 ℃) each of the jig (jig) fixed to both ends of the PET film without the adhesive film of the specimen and One jig is fixed and the other jig is pulled at a rate of 300 mm / min by a length of 1000% of the thickness of the adhesive film (unit: μm) (10 times the initial thickness of the adhesive film, X ₀ ), and then It is maintained for a second, and restored to the same speed (300 mm / min) to the pulled speed, when the length of the adhesive film when the force of 0 kPa is applied to the pressure-sensitive adhesive film is X _f (unit: ㎛), The recovery force (%) was calculated as 2.

[Equation 2]

Recovery Force (%) = (1- (X _f / X ₀ )) × 100

(7) Bubble generation area (%): 50 μm thick PET on one side of the adhesive film (13 cm × 3 cm, thickness 100 μm) and 100 μm thick PET laminated on the back side of the adhesive film Between the parallel frame of 1 cm interval, bent in the 50 ㎛ PET direction so that the horizontal length of the adhesive film is 1/2, aged at 70 ℃, 93% humidity for 24 hours, and optical microscope (Olympus, The image measured by EX-51) is analyzed by Mountech's Mac-view software, and it is the value (%) which measured the ratio of the bubble size to the area to the area.

(8) Refractive index measurement: It measured using ATAGO's DR-M2 multiwavelength abe refractor.

Example Comparative example One 2 3 4 5 One (A) (a1) 60 60 60 60 60 60 (a2) 40 40 40 40 40 40 (B) (b1) 2.5 5 10 - - - (b2) - - - 3 5 - (C) (c1) 0.005 0.005 0.005 0.005 0.005 0.005 (c2) 0.35 0.35 0.35 0.35 0.35 0.35 (D) 0.1 0.1 0.1 - 0.1 0.1 Tg (℃) of adhesive film -36.8 -37.9 -39.8 -36.2 -37.3 -38.4 N _A 1.44 1.44 1.44 1.44 1.44 1.44 | N _A -N _B | 0.01 0.01 0.01 0.02 0.02 - Storage Modulus (KPa) -20 ℃ 129 198 211 185 202 132 25 ℃ 42 54 66 45 54 30 80 ℃ 32 44 57 22 27 8 T-peel Peeling Strength (gf / in) 25 ℃ 584 648 961 672 939 756 60 ℃ 302 385 630 456 626 432 Haze (%) 0.95 1.01 1.12 0.98 1.05 0.87 Haze (%) after 200% extension 1.08 1.16 1.28 1.11 1.19 0.99 Recovery power (%) 47.1 59.3 78.2 48.2 60.5 27.5 Bubble generation area (%) 0 0 0 0 0 2.01

(In Table 1, N _A is the refractive index of the adhesive film state of the (meth) acrylic copolymer itself having a hydroxyl group except nanoparticles, N _B is the refractive index of the nanoparticles, | N _A -N _B | is the nanoparticles Is the difference between the refractive index of the (meth) acrylic copolymer having a refractive index and a hydroxyl group.)

As shown in Table 1, the adhesive film of the embodiment of the present invention is maintained in the viscoelastic properties over a wide temperature range, has excellent physical properties in the recovery force and bubble generation area, as well as low haze (transparency) and excellent It can be seen that the adhesive force.

On the other hand, a comparative example that does not contain nanoparticles does not.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be manufactured in various forms, and a person of ordinary skill in the art to which the present invention pertains has the technical spirit of the present invention. However, it will be understood that other specific forms may be practiced without changing the essential features. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

Claims (25)

Monomer mixtures comprising a (meth) acrylate having a hydroxyl group and a comonomer; And It is a composition comprising a nanoparticle; The nanoparticles comprise a silicone-based polymer, the average particle diameter of about 5 nm to about 800 nm pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition of claim 1, wherein the (meth) acrylate having a hydroxyl group has a glass transition temperature (Tg) of about -80 ° C to about -20 ° C. The method of claim 1, wherein the comonomer is an alkyl (meth) acrylate monomer, a monomer having an ethylene oxide, a monomer having a propylene oxide, a monomer having an amine group, a monomer having an amide group, a monomer having an alkoxy group, a monomer having a phosphoric acid group, At least one of a monomer having a sulfonic acid group, a monomer having a phenyl group, and a monomer having a silane group, The glass transition temperature (Tg) of the comonomer is about -150 ℃ to about 0 ℃ pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition of claim 1, wherein the nanoparticles have a core-shell structure, and glass transition temperatures of the core and the shell satisfy the following Formula 1: [Equation 1] Tg (c) <Tg (s) (In Formula 1, Tg (c) is the glass transition temperature (° C.) of the core, and Tg (s) is the glass transition temperature (° C.) of the shell). The pressure sensitive adhesive composition of claim 4, wherein the glass transition temperature of the core is about −200 ° C. to about −40 ° C., and the glass transition temperature of the shell is about 15 ° C. to about 200 ° C. 6. The pressure-sensitive adhesive composition of claim 4, wherein the core comprises polysiloxane and the shell comprises poly (meth) acrylate. The pressure-sensitive adhesive composition of claim 1, wherein the nanoparticles are included in an amount of about 0.1 part by weight to about 20 parts by weight based on 100 parts by weight of the monomer mixture. The pressure-sensitive adhesive composition of claim 1, wherein the pressure-sensitive adhesive composition further comprises one or more of an initiator and a crosslinking agent. The pressure-sensitive adhesive film formed of any one of the pressure-sensitive adhesive composition of claim 1. The pressure-sensitive adhesive film of claim 9, wherein the pressure-sensitive adhesive film comprises a (meth) acrylic copolymer having a hydroxyl group polymerized from a monomer mixture including a (meth) acrylate having a hydroxyl group and a comonomer. The monomer of claim 10, wherein the (meth) acrylic copolymer having a hydroxyl group comprises about 15% to about 45% by weight of (meth) acrylate having a hydroxyl group and about 55% to about 85% by weight comonomer. Adhesive film polymerized from the mixture. The pressure-sensitive adhesive film of claim 10, wherein the pressure-sensitive adhesive film further includes nanoparticles, and the nanoparticles have a refractive index difference of about 0.05 or less with the (meth) acrylic copolymer having the hydroxyl group. The pressure-sensitive adhesive film of claim 9, wherein the pressure-sensitive adhesive film has a glass transition temperature (Tg) of about 0 ° C. or less. The pressure-sensitive adhesive film of claim 9, wherein the pressure-sensitive adhesive film has a storage modulus of about 10 KPa to about 1,000 KPa at 80 ° C. 11. The pressure-sensitive adhesive film of claim 9, wherein the pressure-sensitive adhesive film has a storage modulus of about 10 KPa to about 1,000 KPa at 25 ° C. 11. The pressure-sensitive adhesive film of claim 9, wherein the pressure-sensitive adhesive film has a storage modulus of about 10 KPa to about 1,000 KPa at −20 ° C. 11. The pressure-sensitive adhesive film of claim 9, wherein the pressure-sensitive adhesive film has a ratio of storage modulus at 80 ° C. and storage modulus at −20 ° C. in a range of about 1: 1 to about 1:20. The pressure-sensitive adhesive film of claim 9, wherein the pressure-sensitive adhesive film has a haze of about 4% or less at a thickness of 100 μm. The pressure-sensitive adhesive film of claim 9, wherein the pressure-sensitive adhesive film has a haze of about 5% or less after 200% stretching at a thickness of 100 μm. The pressure-sensitive adhesive film of claim 9, wherein the pressure-sensitive adhesive film has a recovery force of about 30% to about 98% by 100 μm in thickness. [Equation 2] Recovery Force (%) = (1- (X _f / X ₀ )) × 100 (Equation 2, when the both ends of the PET (polyethylene terephthalate) film (thickness: about 75㎛) of horizontal × vertical (about 50 mm × about 20 mm), respectively called the first end and the second end, The end portions of each of the two PET films are adhered to each other by an X-length (about 20 mm × about 20 mm) adhesive film, and the first end / adhesive film of the PET film (width × length, about 20 mm × about 20 mm) A test piece was prepared in the order of the second end of the PET film, the jig was fixed to both ends of the PET film, one jig was fixed, and the other jig was pulled at a speed of about 300 mm / min. After reaching the length (about 10 times the thickness, X ₀ ) of about 1000% of the thickness (unit: ㎛) of the pressure-sensitive adhesive film is maintained for about 10 seconds, and restored at the same speed as the pulled speed (about 300 mm / min The length of the pressure-sensitive adhesive film elongated when the force of about 0 kPa is applied to the pressure-sensitive adhesive film is X _f (unit: μm)). The pressure-sensitive adhesive film of claim 9, wherein about 50 μm-thick PET and about 100 μm-thick PET are laminated on one surface of the pressure-sensitive adhesive film (about 13 cm × about 3 cm, thickness of about 100 μm). Between the parallel frame of about 1 cm interval, bend in the direction of about 50 ㎛ PET so that the horizontal length of the adhesive film is about 1/2, aging for 24 hours at a temperature of about 70 ℃, humidity of about 93% ), Adhesive film with bubble generation area of about 0%. The pressure-sensitive adhesive film of claim 9, wherein the pressure-sensitive adhesive film has a T-peel peel strength of about 400 gf / in to about 4,000 gf / in at 25 ° C. with respect to the corona treated polyethylene terephthalate (PET) film. The pressure-sensitive adhesive film of claim 9, wherein the pressure-sensitive adhesive film has a T-peel peel strength of about 200 gf / in to about 3,000 gf / in at 60 ° C. with respect to the corona treated polyethylene terephthalate (PET) film. Optical film; And Display member comprising the adhesive film of claim 9 attached to one or both sides of the optical film. The method of claim 24, wherein the optical film is a touch panel, a window, a polarizing plate, a color filter, a retardation film, an elliptical polarizing film, a reflective polarizing film, an antireflection film, a compensation film, a brightness enhancement film, an alignment film, a light diffusion film, glass scattering Prevention film, surface protection film, OLED device barrier layer, plastic LCD substrate, indium tin oxide (ITO), fluorinated tin oxide (FTO), aluminum dopped zinc oxide (AZO), film containing carbon nanotube (CNT), Ag nanowires ( A display member comprising a nanowire-containing film or a graphene-containing film.

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